Balanced slide-valve



(N0 Model.)

A.TH0MS0N.

BALANGBDSLIDB VALVE. No. 337,714. f Patented Mar. 9, 1886.

N PETERS. Pmwuhographer, wasmngwn. D. c.

UNITED STATES PATENT OFFICE.

AROHIE THOMSON, OF OHATTANOOGA, TENNESSEE.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 337,714, dated March 9, 1886.

Application lcd December 7, 1885. Serial No.1`84,979. (No model.)

To all whom it may concern:

Be it known that I, ARCHIE THOMSON, a resident of Chattanooga, in the county of Hamilton and State of Tennessee, have invented certain new and useful Improvements in Balanced Slide-Valves, of which the following is a specication.

My invention relates, first, to means employed for utilizing steam to counterbalance in part or wholly the pressure upon the valve; second,it relates to means for oiling automatically the valves and operative parts, all of which will be fully set forth in the description of the accompanying drawings, making a part of this specification, in whic v Figure 1 is a central vertical cross-section of my improvement. Fig. 2 is a transverse vertical section. Fig. 3 is a top plan view of the oil or check valve. Fig. 4 is a section on line x x, Fig. 2.

A represents the steam-chest, which is of ordinary construction.

1 2 represent the induction and eduction passages leading into the cylinder.

B represents a slide-valve, which is constructed to operate according to the common ordinary slide-valve by covering and uncovering the ports a a, opening into the inductionpassages.

b represents the exhaust-chamber between the ports a a, which is also of ordinary construction, and is provided with the ordinary escape-pipe.

C represents the Valvestem; c, the stuffing-box, which valve and stem are operated by the ordinarylink and eccentric movement.

D represents an upward supplemental extension of the steamchest.

E represents asupplemental cylinder, which is preferably connected to the extension D by screw-bolts. Extension D opens freely into the steam-chest.

F represents aguide, which is provided with two openings, d, for the free admission of steam into the supplemental cylinder E.

G represents a supplemental piston, reciprocating within the cylinder E. It is connected to the valve by a piston-rod, 3, and a link, 4. The top of the valve is recessed to receive the end of the link 4, and a transverse pin, 6, passes through aslot in the link to hold it in position. y

5 represents a pin for connecting the link 4 to the piston-rod 3, which rod passes through an opening in the head of the extension D, which is shown in plan, Fig. 4.

l2 represents a seat on which the piston G rests when there is no pressure in the steamchest.

Piston G may be packed in the ordinary manner, if desired, by packing-rings or other equivalent means.

As Valve B is moved forward link 4 and rod 3 reciprocate the piston G simultaneously with the movement ot the valve B. In order to avoid the adjustment of the parts I elongate the openings in the link 4 at the upper end, below the pin 5, and at the lower end above the pin 6.

The dotted lines in Fig. l show the extent of the movement of the valve at a full stroke of the valve to the left or forward. The full lines show the valve in the act of passing the center, and moving forward to cover the port leading to passage 2, and to uncover the port leading to passage 1, for exhausting through passage l.

The piston G with each full movement of the valve is drawn down and stops at the position shown by dotted lines, Fig. l.

The area of the valve B is shownlarger than the area of the piston G, and hence the pressure upon the valve is slightly greater than the pressure upon the piston, the piston onlyr in part counterbalancing the Weight of steam upon the valve; but the areas may be changed, so as to have an exactly-balanced valve, if desired.

In order to prevent the movement of the piston G and the clattering of the valve when the valve is in motion-as in a locomotivewhen not using steam, I provide slots for the pins 5 and 6 in the connecting-rod 4, so that a full movement of the valve will operate the link without operating the piston. The elongation of the slots for the pivot-holes for the pins 5 and 6 is together equal to the entire distance which the piston G moves. Vhen the steam is off, the piston G drops down to its position, and the elongati'ous in the link 4 IOO same time -to lubricate the seat for the val-ve'- B, as well as the main cylinder and piston. To accomplish this I have provided the following instrumentalities:

H represents the oil-cup the stem of which screws into the cap I lof the cylinder E, vandthe piston-rod 3 extends through the piston G a sufficient distance to come vertically under the orice in the stem of the oil-cup. The

piston-rod 3 is p rovided with a hollow opening or oil-passage, e, leading through it. The

lower end of this rod 3 is enlarged, and re-v ceives the check-valve 7.

8 represents a pin, which stops the descenty of the valve 7.

9 represents a continuation of the open-ing in the rod 3, through which the oil passes' freely when the Valve has dropped down onto its seat 8.

The valve 7 is an ordinary three-winged valve, the oil passing between the wings of the valve, out the opening9,.and down into the opening l0 in the cap of the valve B,Where it is received and held when the engine is idle, and ilows over the edges and down through onto the seat of the valve, through the ports into the passages 1 and 2, for oiling thecylinders and piston.

When steam is admitted into the chest and the piston G rises, the passage 9 is sufficiently large to allow the steam to freely enter and raise the valve 7 against its seat, which stops the admission of oilinto the steam-chest, valves, and cylinders of the engine when it is in operation. As soon as the steam is cut off lthe oil-valve drops back to its seat, and the oil is received into the reservoir 10, for oiling the engine when it is in motion; The check-valve 7 prevents the escape of steam into the oilcup when the steam is applied.

I do not wish to limit myself to the form of check-valve 7, as any form of valve may be employed to close the oil-passage which will admit oil into the steam-chest when the valve is open. z

What I claim as my invention is- 1. In combination with a slidevalve and a supplemental piston, a link provided at each end with a slot, and pins passed through said slots for connecting the link to the'valve and piston, whereby the piston is allowed to remain idle when the valve is moving Without steam-pressure, substantially as described.

2. In combination kwith a slide-valve and a supplemental piston, a piston-rod having a Valved oil-passage leading into the valve- .chamber, and alink for connecting said valve and piston-rod, substantially as described.

3. In combination with a slide-valve, a valve-chamber, a supplemental piston, and a piston-chamber communicating with the valvechamber, a piston-rod having a valved oilpassage, a link havingfa slot at each end,`andVV pins for connectingsaid link'to the piston-rod and slide-valve, substantially as described.

4I In combination ywith the supplemental piston G and piston-rod 3, having theoil-passage leading through said rod, `the valve 7, .y

operated by the pressure of the steam to close the oil-passage When the steam-pressure is operating in the chest, substantially as herein specified. f

In testimony whereof I have hereunto set my hand.

ARcHrs rHoMsoN.

T-itnesses:

RQBERT ZAHNER, M. E. MILLIKAN. 

